Bias Power Regulator Circuit for Isolated Converters with a Wide Output Voltage Range

2. The isolated converter of claim 1, wherein the bias power regulator includes a mode controller configured to select one of the set of modes while a bias supply input voltage provided by the auxiliary winding is less than a threshold.

3. The isolated converter of claim 2, wherein the mode controller is configured to select a constant off-time modulation mode from among the set of modes and to direct the switch controller to provide pulses while the isolated converter has a light load condition, and the bias power regulator is configured to maintain the bias supply output voltage above an undervoltage lockout (UVLO) off threshold for the switch controller in the constant off-time modulation mode.

4. The isolated converter of claim 3, wherein the switch controller is configured to provide a light load signal to the mode controller, and the mode controller is configured to provide periodic pulse requests to the switch controller responsive to the light load signal.

5. The isolated converter of claim 2, wherein the mode controller is configured to select a constant peak-current modulation mode from among the set of modes while the isolated converter does not have a light load condition, and the bias power regulator is configured to adjust the switching frequency of the second switch while maintaining the bias supply output voltage at a target reference in the constant peak-current modulation mode.

6. The isolated converter of claim 1, wherein the isolated converter is adapted to be coupled to a load that includes a USB power delivery adapter.

7. The isolated converter of claim 1, wherein the isolated converter is adapted to be coupled to a load that includes a light-emitting diode (LED) driver.